Abstract: Effects of Mo addition and the reaction temperature on the activity, the selectivity and the anticarbondeposition of over Ni/ZnO catalyst for ethanol steam reforming were studied. The results of reaction at 773K suggested that the activity and selectivity to H2 of Ni/ZnO catalyst were promoted after the appropriate addition of Mo. The activities of the catalysts increased with the increase of the reaction temperature. Ethanol was converted completely at 823K. At 873K, NMZ-2 catalyst, in which the content of Mo was 0.83%, showed the optimum activity, the highest selectivity towards hydrogen and the best stability among the catalysts. The ability of anti-carbon-deposition of NZ can be promoted by addition of Mo, accordingly, the stability of this catalyst is improved. TPR and XRD results show that addition of Mo is contribute to the dispersion of nickel oxide over ZnO and weakens the interaction between Ni oxide and the support. Therefore, the activity, selectivity and stability of Ni/ZnO catalyst are improved.